Evans blue concentration was measured in aliquots of suprachoroidal fluid extracted from enucleated eyes of chicks after 0, 1, 4, 7, and 15 days of recovery from induced myopia
(Fig. 1A) . Evans blue concentration in suprachoroidal fluid of chick eyes after 10 days of form deprivation (0 days of recovery) was significantly lower in treated eyes (18.9 ± 4.4 μg/mL) than in contralateral control eyes (79.1 ±19.9 μg/mL;
P = 0.05; paired
t-test). Evans blue concentration was not significantly elevated in eyes after 1 day of unrestricted vision (recovering eyes, 58.9 ± 22.5 μg/mL) compared with paired contralateral control eyes (20.9 ± 5.9 μg/mL;
P = 0.135; paired
t-test). After 4 days of unrestricted vision, the suprachoroidal fluid levels of Evans blue were significantly elevated in recovering eyes compared with levels in contralateral controls (224.5 ± 20.0 μg/mL vs. 20.2 ± 5.6 μg/mL, respectively;
P < 0.01; paired
t-test). Evans blue levels remained elevated in the suprachoroidal fluid of recovering eyes after 7 days of recovery (180.4 ± 0.38.7 μg/mL) compared with those of contralateral controls (20.1 ± 3.7 μg/mL;
P < 0.05; paired
t-test) but returned to levels similar to those of controls after 15 days of recovery (130.0 ± 47.8 μg/mL in recovering eyes; 33.4 ± 15.8 μg/mL in control eyes;
P = 0.108; paired
t-test). Similar results were obtained when the Evans blue concentration in suprachoroidal fluid was normalized to the plasma concentration of Evans blue
(Fig. 1B) . Comparison of normalized Evans blue levels in the suprachoroidal fluid of control eyes of all treatment groups (0–15 days of recovery) suggested that little change occurred in choroidal permeability in untreated control eyes. Comparison of normalized Evans blue levels in the suprachoroidal fluid of treated eyes after 1 day of unrestricted vision, compared with normalized Evans blue levels in suprachoroidal fluid from form-deprived eyes (0 days of recovery), indicated that significant increases in choroidal permeability occurred in the treated eye after 1 day of unrestricted vision. (
P < 0.05; ANOVA). Results of these experiments confirm and extend the studies of Pendrak et al.,
20 who demonstrated increased vascular permeability in the choroids of chick eyes recovering from form deprivation myopia for 7 days.